Acromag AcroPack AP560, Руководство пользователя

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AcroPack Series AP560 CAN Bus Interface Module
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This Acromag AP560 is a PCI Express Base Specification, Revision 2.1compliant
AcroPack module. The carrier/CPU connects a PCIe bus to the AcroPack
module.
The PCI bus is defined to address three distinct address spaces: I/O, memory,
and configuration space. The AcroPack module can be accessed via the PCIe
bus memory space and configuration spaces, only.
The AcroPack configuration registers are initialized by system software at
power-up to configure the card. The AP560 module is a Plug-and-Play PCIe
card. As a Plug-and-
Play card the board’s base address and system interrupt
request line are not selected via jumpers but are assigned by system software
upon power-up via the configuration registers. A PCIe bus configuration
access is used to access an AcroPack
’s configuration registers.
PCIe Configuration Address Space
When the computer is first powered- up, the computer’s system configuration
software scans the PCIe bus to determine what PCIe devices are present. The
software also determines the configuration requirements of the PCIe card.
The system software accesses the configuration registers to determine how
many blocks of memory space the module requires. It then programs the
board
’s configuration registers with the unique memory address range
assigned.
The configuration registers are also used to indicate that the module requires
an interrupt request line. The system software then programs the
configuration registers with the interrupt request line assigned to the module.
Since this module is relocatable and not fixed in address space, this module’s
device driver must use the mapping information stored in the module’s
Configuration Space registers to determine where the module is mapped in
memory space and which interrupt line will be used.
Configuration Registers
The PCIe specification requires software driven initialization and configuration
via the Configuration Address space. This module provides 512 bytes of
configuration registers for this purpose. The AP560 contains the configuration
registers, shown in Table 3, to facilitate Plug-and-Play compatibility.
The Configuration Registers are accessed via the Configuration Address and
Data Ports. The most important Configuration Registers are the Base Address
Registers and the Interrupt Line Register which must be read to determine the
base address assigned to the AP560 and the interrupt request line that goes
active on an AP560 interrupt request.